1. Field of the Invention
This invention relates to improvements in a zoom lens barrel provided with a single operating ring.
2. Description of the Prior Art
Most of the zoom lenses of wide angle standard lens systems are of the type in which the forwardmost group lens is moved for both zooming and focusing operations, but the lenses of this type have a disadvantage that the light beam is kicked at the short focal length side of the lens if photography up to a macro area is effected only by focusing. In a zoom lens barrel provided with operating rings exclusively used for zooming and focusing, respectively, a construction in which macro focusing can be effected only at the long focal length side to prevent the kick of the light beam at said short focal length side is disclosed in U.S. Pat. No. 4,210,387, but in a zoom lens provided with a single operating ring, change-over of the distance limit range has been difficult because the operating ring moves back and forth.